Thread: Sliding dovetails

Hi , regarding the type of hand saw you are using, is it the typical western style or is it the japanese style hand saw ? If you use a japanese saw the teeth cut on the pull stroke where as western saws cut on the push stroke. Using a japanese style saw may allow you to achieve the results you are looking for.
Cheers Alby

Originally Posted by Berlin

We've had a lot if threads dealing with tools recently and fewer than normal covering techniques, so I thought I'd pose a tricky (for me at least!) question for the brains trust.

How do you (ignore if you will for the moment alternative joints) cut a stopped, tapered, sliding dovetail? It seems like black magic but there must be a knack to it!

I have been successfully cutting the channel of through sliding DT's with a back saw and angled guide block to kerf in and then cleaning up with a chisel and router plane. I get a pretty neat result in reasonably short order but without cutting the teeth backwards what are the options for stopping the trench? I do have the parts for a stair saw which is designed for just this task but it's only 150mm long and seems like a tedious way to cut a channel...

I didn't try yet, but I thought of boring/chopping a clearance mortice at the blind end for the saw to run into... ?

Also, the tapered edge is typically on top isn't it?

Any advice or experience would be greatly appreciated. I know no one's going to my handywork (just as well perhaps ) but I'd like to master it.

Cheers

Stopped, tapered,sliding dovetails-by hand! Amazing.

Perhaps, though I have never tried it and I have really no idea-but perhaps you could cut a basic stopped trench (dado) first. I suppose that there would then be some sort of router or router plane you could use to shape the trench but I suppose you would have to clean up the end of the trench with a chisel.

The Japanese tend to be quite into their sliding dovetails, and they even have special saws for making them - they are discussed in Toshio Odate's book. Not sure where you'd get one mind. Perhaps Stu from toolsfromjapan might be able to help.

Originally Posted by Berlin

I didn't try yet, but I thought of boring/chopping a clearance mortice at the blind end for the saw to run into... ?

Also, the tapered edge is typically on top isn't it?

No practical experience here, as you know, but I've certainly read of a hole drilled at the stop for a standard trench, so I guess the same could apply.

I think I read Stanley had a plane for plowing (half?) a dovetail trench - pretty sure Patrick Leach was a being a bit cruel about it

When you say tapered edge on top ... do you mean as opposed to a V-shaped (ok inverted A), and open, trench?

My understanding is of a constant-depth trench, with vertically angled walls, and decreasing in width along its length. I'm guessing that could either be one side straight and the other angled, or both angling in toward a centre line.

OK. There's a minute of your life you'll never get back again

Paul

I have always cut them with a backsaw and chisel, beginning with digging a mortice at the stop point. I make the angled cut in the trench by eye and then make the angle on the dovetail to suit it.

On thin-ish stock, I use an old woman's tooth to clean the bottom of the trench, but if the stock is thick enough, I just chisel out a surfeit of waste to ensure the dovetail doesn't bind on the bottom of the trench.

I cut some sliding dovetails recently when making my kneehole desk and I used a little Veritas OWT to tidy up the bottom of the trenches, but it's a damned nuisance of a tool and will require modification if I'm to use it again.

This may not be the accepted methodology, but it appears to be how it was performed for several hundred years and it works for me with the tools I have.

If you are doing them by hand for shelving or horizontal bracing save yourself a lot of extra work and use a half tail which is quite acceptable for hand tooling and serves the purpose just as well as double sided routers slides.

P.S. The Half tail is cut on the downward side of the shelf or stretcher.

So the top half resembles a normal tenon and mortise (dado) joint and the
bottom half resembles a half blind dovetail.


Cheers



Steve

I meant to mention; sliding dovetails are normally tapered so they are free-fitting right up until the point they reach their final position. The taper need only be 1/16" over several feet and is on the dovetail side of the joint.

Originally Posted by Woodwould

I meant to mention; sliding dovetails are normally tapered so they are free-fitting right up until the point they reach their final position. The taper need only be 1/16" over several feet and is on the dovetail side of the joint.

Bril, thanks for the info Woodwould! How it's been done for the last few centuries is exactly what I wanted to know.

I mentioned I use a router plane but actually it's a big wooden bodied OWT, not one of these flash things with a depth adjuster

Fineboxes, I don't find it any harder really to cut the angle on both sides but I can see it removes one variable when it comes to getting the joint square. I'll give it a try.

Thanks everyone for the input. I'm using western saws and recently got rid of my last Japanese one. It cut like fury but I could never get a reliably straight cut the way I can with Western saws. It must be a muscle memory thing or something

I use my new DT plane for the male part but I can't imagine a plane for the trench being a time saver. That part happens pretty fast anyway. Happy to be convinced otherwise though

Cheers

For decades I have always cut the trench with a router, now here I am being put to shame by relative newcomers who are cheerfully tackling the whole joint without burning a single electron.

When using a router to cut the trench, a slight taper can be introduced very easily by moving the guide over a fraction at one end after the initial square cut (works well as lng as I remember to move it in the correct direction for the housing on the other end!). As WW says, the taper need only be very slight - about a mm over the entire width of a 450mm wide shelf works ok for me. I've also been cutting the tails with a router & simple jig to remove most of the waste, then refining & fitting with a paring chisel, but about a year or two back, I made a very simple dovetail plane to make it easier to clean up the tail section. It doesn't have a nicker, & I didn't include a fence, as I use the pre-cut shoulder to register the side of the plane. It does an excellent job, and makes fitting the tail sections a breeze. With a fence & nicker, I'm sure it could do the whole job in not much more time, and with a whole lot less mess than my curent approach.

I have been thinking about moving to all hand construction for these joints since a post by Derek Cohen, some time back, discussing suitable saw designs for the trench cuts. I think a longish 'stair saw' style saw that cuts on the pull stroke might suit the purpose well. Given that I detest routers with their noise & attendant mess, and their potential to destroy a piece of valuable wood in the blink of an eye, I have now resolved to make all future SDs the safe and quiet way. So thanks for a timely post, Matt - you've prompted me to get busy & make a style of saw I haven't tried yet....

Cheers,

Originally Posted by IanW

...you've prompted me to get busy & make a style of saw I haven't tried yet....

!!SNAP!!

The trap closes

Originally Posted by fineboxes

P.S. The Half tail is cut on the downward side of the shelf or stretcher.
So the top half resembles a normal tenon and mortise (dado) joint and the
bottom half resembles a half blind dovetail.
Cheers
Steve

Aaaahhh. Stupidity will out

I was picturing a tabletop turned upside-down to receive the trench, not a vertical member like the side of a chest etc.
At least the dept of memory hasn't entirely succumbed to the dept of verbal diarrhoea ... #444 Dovetail plane

"Runner-up to the Mr. Stupid Plane Pageant (in the event that Mr. Stupid Plane can no longer remain in that role, the runner-up shall assume the position and do guest appearances either on a televised workshop program decorated in plaid or Vegematic infomercials). This is a plane that only a mother or Rube Goldberg could love."

Cheers,
Paul

Instruction manual:
http://www.tooltrip.com/tooltrip9/st...isc/444man.pdf

Iv'e done them with the back saw ,angled block to as far as I can get then chisel and OWT router.
I have to do Eight of them soon and will be going with the router In a sled or a frame, speed is what I need on this one .

With the male side of things I have two antique planes that will cut them if I want. The German one is a beautiful plane with an adjustable fence and brass wing nuts and nicker blade that cuts half of the dovetail across the end of a board, The British version does not have a fence , is Beech and has a steel sole screwed in , it was made that way .
The German plane is made from a timber I have not seen before .someone once said it could be Hornbeam ? I can put pictures up if I can find time .someone , Berlin maybe ? might be able to identify the wood.

Rob.

Originally Posted by auscab

The German plane is made from a timber I have not seen before .someone once said it could be Hornbeam ?

Hornbeam would be right for a European plane.

Red and white beech, ash and hornbeam are all fairly common in German planes, although as I've been reminded recently, confidently identifying timber species from photos on the net is a good way to make a fool of one's self.

... But here I go without even seeing it: Ash- fraxinus excelsior.

:P